I created a scrolling overlay in a separate project, and would like to use this overlay in an existing project. Importing images seems straightforward, but I can't seem to figure out how to properly import the event sheets and layouts. They all show up as XML files. Is there a way to convert the XML files back to actual event sheets and layouts usable in Construct 2?

You have to first make sure the project will have every global value and object with the EXACT same names and properties as the event sheet/layout you want to import.

Then you have to edit a construct file via text editor to add the references to to the event sheets/layouts you're importing.

I managed to do this in the past, but it took a long time to find all the references and get it all right so the end result didn't hang up on loading or crash. It was only worth it because despite the hard work, it was still a little less work that redoing everything from scratch.

Unfortunately it's been well over a year and I don't have any time to redo such a thing for additional detail, tips, or tutorials. Maybe someone else has done it as well and can shed additional light.. but again, it is possible, just really tough, and completely manual work. with text editors.

Copy/pasting the entire event sheet in an empty one should work. However, you need to be sure that all objects (same types and names) and global variables referenced in your "copy" selection exists in your destination project, otherwise it won't paste at all.